Circuit service (Circuit Service, CS) network is a wireless network for providing circuit service such as voice call and the like, and coverage of 2G/3G wireless networks such as a GSM, a WCDMA and the like is quite universal. Meanwhile, with development of network technology, packet service (Packet Service, PS) networks specialized in providing data service, such as long term evolution (Long Term Evolution, LTE), system architecture evolution (System Architecture Evolution, SAE), high-speed packet access (High-Speed Packet Access, HSPA), high-speed packet access evolution (High-Speed Packet Access Evolution, HSPA+) and so forth, also have broad coverage. Therefore, a CS network and a PS network coexist in a current communication network, and an operator may provide circuit service for a subscriber by using a 2G/3G network or provide data service for a subscriber by using an LTE network. A user equipment (User Equipment, UE) is a multi-mode terminal, and may perform circuit service in a CS network or perform data service in a PS network according to requirements of a subscriber.
For the moment, an MSC redirects all UEs to the LTE, thereby raising a problem that a UE which does not need to return to the LTE network mistakenly returns to the LTE network.